/*
silverPDF is sponsored by Aleyant Systems (http://www.aleyant.com)

silverPDF is based on PdfSharp (http://www.pdfsharp.net) and iTextSharp (http://itextsharp.sourceforge.net)

Developers: Ai_boy (aka Oleksii Okhrymenko)

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above information and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR SPONSORS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

*/
#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2008 empira Software GmbH, Cologne (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Diagnostics;
using System.Collections;
using System.Text;
using System.IO;
using PdfSharp.Pdf.Advanced;
using PdfSharp.Drawing;
using PdfSharp.Fonts.TrueType;
using PdfSharp.Internal;
using System.Collections.Generic;

namespace PdfSharp.Pdf.Advanced
{
  /// <summary>
  /// Represents the imported objects of an external document. Used to cache objects that are
  /// already imported when a PdfFormXObject is added to a page.
  /// </summary>
  internal sealed class PdfImportedObjectTable
  {
    /// <summary>
    /// Initializes a new instance of this class with the document the objects are imported from.
    /// </summary>
    public PdfImportedObjectTable(PdfDocument owner, PdfDocument externalDocument)
    {
      if (owner == null)
        throw new ArgumentNullException("owner");
      if (externalDocument == null)
        throw new ArgumentNullException("externalDocument");
      this.owner = owner;
      this.externalDocumentHandle = externalDocument.Handle;
      this.xObjects = new PdfFormXObject[externalDocument.PageCount];
    }
    PdfFormXObject[] xObjects;

    /// <summary>
    /// Gets the document this table belongs to.
    /// </summary>
    public PdfDocument Owner
    {
      get { return this.owner; }
    }
    PdfDocument owner;

    /// <summary>
    /// Gets the external document, or null, if the external document is garbage collected.
    /// </summary>
    public PdfDocument ExternalDocument
    {
      get 
      {
        if (this.externalDocumentHandle.IsAlive)
          return this.externalDocumentHandle.Target;
        return null; 
      }
    }
    PdfDocument.DocumentHandle externalDocumentHandle;

    public PdfFormXObject GetXObject(int pageNumber)
    {
      return this.xObjects[pageNumber - 1];
    }

    public void SetXObject(int pageNumber, PdfFormXObject xObject)
    {
      this.xObjects[pageNumber - 1] = xObject;
    }

    /// <summary>
    /// Indicates whether the specified object is already imported.
    /// </summary>
    public bool Contains(PdfObjectID externalID)
    {
      return this.externalIDs.ContainsKey(externalID.ToString());
    }

    /// <summary>
    /// Adds a cloned object to this table.
    /// </summary>
    /// <param name="externalID">The object identifier in the forein object.</param>
    /// <param name="iref">The cross reference to the clone of the forein object, which belongs to
    /// this document. In general the clone has a different object identifier.</param>
    public void Add(PdfObjectID externalID, PdfReference iref)
    {
      this.externalIDs[externalID.ToString()] = iref;
    }

    /// <summary>
    /// Gets the cloned object that corresponds to the specified external identifier.
    /// </summary>
    public PdfReference this[PdfObjectID externalID]
    {
      get { return (PdfReference)this.externalIDs[externalID.ToString()]; }
    }

    /// <summary>
    /// Maps external object identifiers to cross reference entries of the importing document
    /// {PdfObjectID -> PdfReference}.
    /// </summary>
    Hastable externalIDs = new Hastable();
  }
}
